text: Other enzymes that may be used for asymmetric ester hydrolysis include electric eel acetylcholinesterase, chymotrypsin, and Baker's yeast. The substrate scope of these enzymes differs from PLE, and in some cases they may provide hydrolyzed products in higher yield or enantioselectivity than PLE. Microorganisms may also be used for enantioselective hydrolysis; however, difficulties associated with the handling of microorganisms have made these methods unpopular for organic synthesis.
  Nonenzymatic methods for the differentiation of enantiotopic groups employ chiral catalysts or auxiliaries. For instance, the introduction of a chiral leaving group on both carboxylic acid groups of a meso diacid leads to selective attack by an achiral nucleophile at one of the (now) diastereotopic carbonyl groups.